ok - thanks again for the feedback on this.  I've put beta4 online in the usual place:

http://www.cs.cmu.edu/~dga/ptsminer/

Along with a static build to address the gentoo library versioning issue.

I'm kind of proud of this one - it's the first of the Haswell builds that cracks 500 cpm on a non-overclocked CPU.  I haven't quite determined if 6 or 7 threads is better, but it's one of those two settings.

Delta from beta3:
  - Uses about 20MB less memory per thread
  - Further optimized sha512 computation code
  - Static build is now part of my default build chain, so we'll keep this one around.
  - Still 3% advanced-build dev fee, but I hope that the 170cpm you'll get more than any other miner should more than compensate for that.  :-)